AUSTRALIA - JAPAN SYMPOSIUM
AUSTRALIA - JAPAN SYMPOSIUM ON EARTH SYSTEMS SCIENCE
AND ON NANOMATERIALS
Canberra, 21 November 2006
Present status of climate system modelling and its future
Professor Akimasa Sumi, Executive Director, Transdisciplinary Initiative for Global Sustainability Center for Climate System Research,
The University of Tokyo, Japan
Professor Akimasa Sumi received his PhD in Atmospheric Science from the University of Tokyo in 1985. He had
been working for the numerical weather prediction in Japan Meteorological Agency from 1973-1985 and then
moved to the department of geophysics, the University of Tokyo in 1985. He had been engaged in ENSO and
Monsoon Studies and devoted himself to TOGA and CLIVAR and the establishment of CCSR. In 1991, he was
appointed a professor in CCSR and the director in 1994-2003. Now, he is appointed as the executive director of
the TIGS, the University of Tokyo.
In order to achieve a reliable simulation of the Global Warming, more horizontal and vertical resolution and more processes are required. For this, a huge computer resource is necessary. The Earth Simulator was developed for this purpose, then, we decided to develop a high resolution climate model jointly by CCSR (Center for Climate System Research), NIES (National Institute for Environmental Sciences) and FRCGC (Frontier Research Center for Global Change) to assess the regional climate change. Its atmospheric component is T106L56 AGCM and the oceanic component is 1/4 x 1/6 OGCM with 48 levels. It has an interactive aerosol mode and the direct and indirect effects are included. On the other hand, the Earth System model is being developed in FRCGC.
Simulation of the present climate and the future climate based on IPCC SRES have been conducted. The global warming simulation has been submitted to IPCC AR4. It is noted that performance of the simulation is improved in many areas, and regional phenomena such as the Baiu is well represented. However, there remain many issues. One of the biggest issues is a poor simulation of SPCZ, and weak amplitude of ENSO. Further effort is necessary.
It is noteworthy that the Kuroshio around Japan is well represented in the climate model. It is shown that ocean current system around Japan in the warmer climate is similar to that in the present climate, although current speed and SST is increased. In the future, much attention will be paid to the regional climate change, especially that in the marginal seas. For that purpose, the high resolution climate model becomes an important role.
